1. Field of the Invention
This invention involves novel anhydride-functional primary alkyl halides having the structure: ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are each individually hydrogen, or methyl, and the total number of carbons in R.sup.1 and R.sup.2 and R.sup.3 combined is two or less.
The anhydride-functional primary halides are useful as corrosion or scale inhibitors, thickeners, dispersants, neutralizing agents, and as crosslinking agents for compounds having functional groups, such as epoxide groups, which are reactive with anhydride groups. Additionally, due to the primary alkyl halide functionality, these compounds are especially useful as reactants in nucleophilic substitution reactions. In nucleophilic substitution reactions, these primary halides can be reacted with nucleophilic reagents, such as carboxylic acid salts, which are relatively unreactive with anhydride groups.
The anhydride-functional primary alkyl halides of this invention have a variety of potential applications due to their combination of reactive primary halide and reactive anhydride sites. Either the anhydride or the halide group could be reacted first, followed, if desired, by subsequent reaction of the other functionality. For example, the anhydride group could be reacted with hydroxyl groups on an alcohol or polyol to provide a product having a pendant primary alkyl halide group. Alternatively, the primary alkyl halide functionality could be reacted first, such as in an alkylation reaction with a carboxylic acid salt, to provide a product having pendant anhydride functionality. This anhydride-functional product could then be utilized as a crosslinker, for example, or the anhydride group could be hydrolyzed to produce a diacid-functional material. The relatively short alkyl chain length, the primary halide group, and the reactivity of the substituted succinic anhydride group combine to provide the unique properties of this material.
2. Description of the Prior Art
Alkyl substituted succinic anhydrides are known in the art. U.S. Pat. No. 4,209,411 teaches C.sub.12 to C.sub.22 2-alkenyl-2,3-dialkyl or 2,3-cyclo-alkenyl substituted succinic acid anhydrides or corresponding acids and indicates that the olefin precursor could be halogenated prior to reaction with the maleic anhydride to produce the substituted succinic anhydride. U.S. Pat. No. 4,661,275 teaches C.sub.8 to C.sub.40 hydrocarbyl group substituted succinic anhydrides. The hydrocarbyl-based substituents could be derived from chlorinated olefins. U.S. Pat. No. 4,664,826 teaches hydrocarbon substituted succinic anhydride materials wherein the aliphatic group is typically a C.sub.2 to about C.sub.50 aliphatic hydrocarbon group which could contain a halogen. U.S. Pat. No. 4,770,799 teaches hydrocarbon substituted succinic anhydride materials wherein the hydrocarbon groups contain from about 6 to about 42 carbon atoms and could include halogen substituents.